Recent content by Dethrone

  1. Dethrone

    MHB Challenging Classical Mechanics Problems: Can You Solve Them?

    1.5 is related to d'Alembert's principle. We can analyze the dynamics of an accelerating frame of reference (i.e non-inertial) by adding a fictitious force. Since the force in system A is $m*100$, then a fictitious force of $m*10$ must be added to system B so that the dynamics in both systems...
  2. Dethrone

    MHB Is the given function a solution of the differential equation?

    A bunch of typos but it's correct. First one it's $3 \cdot (t/3)$, and second one you copied $3e^{-t}$ twice.
  3. Dethrone

    Math Pet Peeves: Share Yours Here!

    I used to have a prof. that would say even 1 + 1 = 2 wasn't obvious to him... to motivate the axiom and properties of real numbers. (Rofl) He would later go on and state trivial limits, etc., basically anything 'obvious', was not obvious to him, to motivate the rigorous treatment of those concepts.
  4. Dethrone

    MHB Is infinity / infinity equal to 1?

    You can't do $\frac{\infty}{\infty}=\infty^{1-1}=\infty^0$ ... that is, treating infinity as if it were a number; otherwise, you'd get all sorts of weird results.
  5. Dethrone

    MHB Can You Outrun a Velociraptor in a Circular Enclosure?

    Wait until the velociraptor sleeps, then run out. Maybe I'm thinking about this in the wrong way, but is the motion of the velociraptor deterministic? That is, if I'm at the center of the circle and move along the line connecting the velociraptor and the human, does the velociraptor move left...
  6. Dethrone

    MHB What are the steps to finding an oblique asymptote for a rational function?

    Yes Because the oblique asymptote is a line that is neither horizontal (horizontal asymptote) nor vertical (vertical asymptote), but slanted.
  7. Dethrone

    MHB How can the given equation be verified without using a calculator?

    It comes right from the identity $\cos\left({\theta+\pi/2}\right)=-\sin\left({\theta}\right)$, or just think about it geometrically. Draw a cosine shifted to the left by $\pi/2$ and compare it with a regular sine wave. Or, apply the cosine addition formulas if you're familiar with them.
  8. Dethrone

    MHB Is 2/3 Always the Same as 4/6?

    It really depends if you assume the question is referring to the same object, otherwise we can argue that one pie could be larger than the other. If we can assume they are different sizes, then what stops us from assuming they have to even be the same object? 2/3 of a pizza vs. 4/6 of a pie. I...
  9. Dethrone

    MHB Integration by parts, Partial fraction expansion, Improper Integrals

    2. Correct 3. Yes, notice that it's an odd function $f(-x)=-f(x)$ so the "areas" cancel out. 4. Might want to check your math here a bit. The answer is correct ($A=2$), but $B=3$ and $C=-2$. Also, $\lim_{{x}\to{\infty}}(e^{-x})=\lim_{{x}\to{\infty}}1/e^x=0$ since the denominator goes to infinity.
  10. Dethrone

    MHB Layout Notation for matrix calculus

    Hi, I guess this could be a rather silly question, but I got a bit confused about the "numerator layout notation" and "denominator layout notation" when working with matrix differentiation...
  11. Dethrone

    MHB Eb3 Velocity and Time: Calculate $V_{av}, v_{av}$, and Time to Fly $3.5 \ km$

    1. Correct 2. Correct, might want to include units. 3. Correct.
  12. Dethrone

    MHB Combination of a Smile and a Frown ....

    For future reference, there's also Detexify LaTeX handwritten symbol recognition
  13. Dethrone

    MHB Integrating the Square Root of a Fraction with a Radical

    Are you sure you did not mean $\int \frac{\sqrt{x^2-4}}{x}\,\mathrm{d}x$?
  14. Dethrone

    MHB Can high school math prove this inequality?

    If we let $a$ and $b$ be $n$ dimensional (euclidean) vectors, then your statement follows directly from the reverse triangle inequality, which is a high-school concept. Now if you're asking for the proof of the triangle inequality, since I'm lazy I'll just say it is geometrically intuitive.
Back
Top